lets deal with Alex first Trev
AL if your a 31" waist im surprised. Im a 30" and can sometimes get in a 28". You will be a medium
Yes you can get in a small bibshort but they may be tight on your legs a bit. Get a medium and 35miles in your ride you wont be riding no hands trying to re adjust your meat and two veg. There sorted.
trevor whats happening with your gears
and why is the ride better my friend. dont worry these things are easily sorted.